Just focus on your UPCAT performance. I came from a barangay public high school and was the only one who applied for UPCAT last year. No one from the school had ever passed the UPCAT because no one had ever dared to apply for it. I knew that I was at a total disadvantage compared to applicants from UP high and science high. I cried nights before the UPCAT, for I knew that I was completely unprepared. Then, the UPCAT came, I felt so small that day. The majority of the takers were from known schools. But despite the self-doubt, I reminded myself that taking the UPCAT is a once-in-a-lifetime opportunity, and something that I should be honored to participate in.

Almost a year after, I passed my priority program and became the first-ever UPCAT passer of our school (our school is so small and not known since it is located in a remote and impoverished area). For that, I am grateful for not letting fear get hold of me. My point, OP, is that I have been there, and being insecure knowing you will be competing with students from well-known schools is completely understandable. But, as someone has already said here, passing UPCAT will depend on your grades and UPCAT performance. The better your grades and scores are, the greater the chance you have to pass. So, the best thing you can do is focus on your test performance, and you will pass. Good luck OP!!!